The Palace add-on mission which is in the Access Granted DLC pack has 10 Hard Drives which can be collected. If you are successful in finding all these Hard Drives you will be able to unlock the final mission.
Beside the vertical tram line go up in the hills to find this hard drive. Jump-off the highway and run on the dirt road which leads to the fenced section at the top.
Find the hard drive by moving along the concrete structure and search the roof top.
If you keep going stratigh from the stadium you will see a huge "FOOD" sign. Go around it then go through the stairs and jump down on the roof. From here use the air-conditioning unit to go up on the higher roof to your left and find the Hard Drive.
From the stadium reach the "Cheesy Beefy" burger sign, it will be right in front of the Bakery. After you drive down the alley take a left from the parking lot. When you see a wooden structure, clim on the ladder to find the Hard Drive.
Go in the opposite direction from the stadium to the brick building and a find a lift which will help you to reach up. You will find the Hard Driveon the left of the ledge.
You will find this Hard Drive in the north-west region of Pawnee. Find the road from the old Satellite facility on which you will see an Abandoned red building. Go in the garage and find the Hard Drive on the ground
Go bridge which will be under construction, use the metal grating bridge to cross the platform. Jump down and reach the lower level where there will be rocks. There will be a Hard Drive lying near the right railing.
From the bridge go on the road in the southwest direction. Keep going till you find a dirt road, from here you will see thin lines which are more dirt roads, onse you reach walk up to the lodge and reach the metal roof near the ledge.
There is a Hard Drive in the north eastern part of the Loop. Reach the left most block and enter the alleyway. There will be a ladder above a red garbage bin, climb up and keep going right till you reach the air conditioner unit. Now jump over the railing and go across the rooftop and keep going higher. Open the door marked with graffiti, find the Hard Drive to the right.
Climb on the green fence outside the docks and search in the grass, you will find the disc here.
You will find a brick wall in the lowest part of the map, find the Hard Drive there.
Also checkout the Watch Dogs Complete Walkthrough for Campaign missions - All Chapters.
